Which C.S. Lewis book collects his BBC radio broadcasts on Christianity?

Mere Christianity collects C.S. Lewis’s BBC radio broadcasts on Christianity.

The broadcasts began in 1941 during the Second World War, when Lewis was invited to speak about Christian belief to a national radio audience. He delivered several series of talks between 1941 and 1944. The talks were later revised, combined, and published in book form as Mere Christianity.

Lewis aimed to explain beliefs shared by the major Christian traditions rather than argue for one denomination. He used everyday language, moral reasoning, analogies, and examples from ordinary experience. The book’s title refers to what Lewis presented as the common core of Christianity.

The original broadcasts were not delivered as one uninterrupted book. Their later arrangement created the familiar sections “Right and Wrong as a Clue to the Meaning of the Universe,” “What Christians Believe,” and “Christian Behaviour.” Readers sometimes date the book to 1941 because that is when the first broadcasts began, but the book edition appeared later, in 1952.